The use of syringes to retain a fluid, such as a medicament, is well known. Devices including syringe positioning apparatus have also been heretofore suggested and/or utilized to control delivery of medicament from the syringe by controlling the movement of the syringe piston (see for example U.S. Pat. Nos. 4,255,096 and 2,764,980).
Prior devices for controlling movement of the syringe piston have, however, not proved to be fully effective, at least for all intended purposes. Some prior known devices have, for example, lacked simplicity of structure and/or operation, have not provided for ease of interchange of disposable elements, have been ineffective in precisely controlling medicament delivery, have lacked the ability to deliver changing amounts of medicament over different time periods, have lacked safeguards against undesired use, and/or have not been fully dependable in operation.